<template>
  <div>
    <nav-bar class="nav-bar">
      <template v-slot:default>
        购物车&nbsp;&nbsp;(<span style="color:red"> &nbsp;&nbsp;{{$store.state.cartCount}}&nbsp;&nbsp; </span>)
      </template>
    </nav-bar>
    <div class="cart-box">
      <div class="cart-body">
        <van-checkbox-group ref="checkboxGroup" @change="groupChange" v-model="result">
          <van-swipe-cell :right-width="50" v-for="(item,index) in list" :key="index">
            <div class="good-item">
              <van-checkbox :name="item.id" />
              <div class="good-img"><img src="~assets/images/11.png" alt=""></div>
              <div class="good-desc">
                <div class="good-title">
                  <span>{{item.goods.title}}</span>
                  <span>×{{item.goods.stock}}</span>
                </div>
                <div class="good-btn">
                  <div class="price"><small>¥</small>{{item.goods.price+'.00'}}</div>
                  <van-stepper integer :min="1" :max="item.goods.stock" :model-value="item.num" :name="item.id"
                    async-change @change="onChange" />
                </div>
              </div>
            </div>
            <template #right>
              <van-button square icon="delete" type="danger" class="delete-button" @click="deleteGood(item.id)" />
            </template>
          </van-swipe-cell>
        </van-checkbox-group>
      </div>
      <van-submit-bar class="submit-all" :price="total * 100" @submit="onSubmit" button-text="结算">
        <van-checkbox @click="allCheck" v-model:checked="checkAll">全选</van-checkbox>
      </van-submit-bar>
      <div class="empty" v-if="!list.length">
        <img class="empty-cart" src="~assets/images/empty-car.png" alt="空购物车">
        <div class="title">购物车空空如也</div>
        <van-button round color="#1baeae" type="primary" block @click="goTo">前往选购</van-button>
      </div>

    </div>

  </div>
</template>

<script>
  import {
    ref,
    reactive,
    toRefs,
    onMounted,
    computed
  } from 'vue';
  import {
    useRouter
  } from 'vue-router';
  import {
    useStore
  } from 'vuex';
  import {
    getCart,
    deleteCartItem,
    checkedCart,
    modifyCart
  } from 'network/cart';
  import {
    Toast
  } from 'vant';
  import NavBar from "components/common/navbar/NavBar"
  export default {
    name: 'ShopCart',
    setup() {
      const router = useRouter()
      const store = useStore()

      //数据模型，状态
      const state = reactive({
        list: [],
        result: [], //购物车id数组
        checkAll: true
      })

      //初始化购物车数据
      const init = () => {
        Toast.loading({
          message: '加载中...',
          forbidClick: true
        })

        getCart('include=goods').then(res => {
          state.list = res.data

          state.result = res.data.filter(n =>
            n.is_checked == 1
          ).map(item =>
            item.id
          )

          Toast.clear()
        })
      }

      onMounted(() => {
        init()
      })

      //通过计算属性 计算总价
      const total = computed(() => {
        let sum = 0;

        state.list.filter(item => state.result.includes(item.id)).forEach(item => {
          sum += parseInt(item.num) * parseFloat(item.goods.price);
        })
        return sum;
      })

      //异步改变购物车数量
      const onChange = (value, detail) => {
        Toast.loading({
          message: '加载中...',
          forbidClick: true
        })
        modifyCart(detail.name, {
          num: value
        }).then(res => {
          //将在onMounted中的list中的num也要改变
          state.list.forEach(item => {
            if (item.id == detail.name) {
              item.num = value
            }
          })
          Toast.clear()
        })
      }

      //复选框改变处理事件
      const groupChange = (result) => {
        if (result.length == state.list.length) {
          state.checkAll = true
        } else {
          state.checkAll = false
        }
        state.result = result
        //改变数据表中的选中状态
        checkedCart({
          cart_ids: result
        })
      }

      const allCheck = () => {
        if (!state.checkAll) {
          state.result = state.list.map(item => item.id)
          state.checkAll = true
        } else {
          state.result = []
          state.checkAll = false
        }
      }

      //删除购物车商品
      const deleteGood = (id) => {
        deleteCartItem(id).then(res => {
          init(); //重新初始化
          store.dispatch('updateCart') //改变vuex中的状态数量
        })
      }

      //前往购物
      const goTo = () => {
        router.push({
          path: '/home'
        })
      }

      //创建订单
      const onSubmit = () => {
        if (state.result.length == 0) {
          Toast.fail('请选择商品进行结算！')
          return;
        } else {
          router.push({
            path: '/createorder'
          })
        }
      }

      return {
        ...toRefs(state),
        goTo,
        onChange,
        groupChange,
        allCheck,
        deleteGood,
        total,
        onSubmit
      }
    },
    components: {
      NavBar
    }
  }
</script>

<style scoped lang="scss">
  .cart-box {
    .cart-body {
      margin: 60px 0 100px 0;
      padding-left: 10px;

      .good-item {
        display: flex;

        .good-img {
          img {
            width: 100px;
            height: auto;
          }
        }

        .good-desc {
          display: flex;
          flex-direction: column;
          justify-content: space-between;
          flex: 1;
          padding: 20px;

          .good-title {
            display: flex;
            justify-content: space-between;
          }

          .good-btn {
            display: flex;
            justify-content: space-between;

            .price {
              font-size: 16px;
              color: red;
              line-height: 28px;
            }

            .van-icon-delete {
              font-size: 20px;
              margin-top: 4px;
            }
          }
        }
      }

      .delete-button {
        width: 50px;
        height: 100%;
      }
    }

    .empty {
      width: 50%;
      margin: 0 auto;
      text-align: center;
      margin-top: 200px;

      .empty-cart {
        width: 150px;
        margin-bottom: 20px;
      }

      .van-icon-smile-o {
        font-size: 50px;
      }

      .title {
        font-size: 16px;
        margin-bottom: 20px;
      }
    }

    .submit-all {
      margin-bottom: 50px;

      .van-checkbox {
        margin-left: 0px
      }

      .van-submit-bar__text {
        margin-right: 10px
      }

      .van-submit-bar__button {
        background: red;
      }
    }

    .van-checkbox__icon--checked .van-icon {
      background-color: red;
      border-color: red;
    }
  }
</style>